Electric spade terminal receptacle



Dec. 13, 1955 BERGAN 2,727,219

ELECTRIC SPADE TERMINAL RECEPTACLE Filed Sept. 17, 1951 INVENTOR. MARTIN D. BERGAN ATTORNEY United States Patent Ofiice 2,727,219 Patented Dec. 13, 1955 ELECTRIC SPADE TERMINAL RECEPTACLE Martin D. Bergan, Westfield, N. 3., assignor to The Thomas & Betts Co., Elizabeth, N. J., a corporation ofNewJersey Application September 17, 1951, Serial No. 246,992

1 Claim. (Cl. 339258) The invention presented herein relates to connectors. More especially it pertains to a new and useful electric spade terminal receptacle for manually making quick-connect and disconnect contact engagement with conventional terminals on electrical apparatus. This new terminal receptacle is for use where it is desired to have a freerelease, plug-in and pull-out connection, as distinguished from a latching-type of disconnector.

In the variety of electrical wiring installations, there is need for improvement in single conductor (one-wire) terminals of the receptacle type permanently connected on the end of a flexible wire and suited for manual operation in making plug-in or plug-on quick-disconnect electrical contact engagement with conventional terminals of panel boards, condensers, batteries, and other electrical apparatus to which current is either fed thereto or received therefrom.

This invention seeks to provide a novel electrical terminal receptacle which is mobile and convenient, on a length of flexible wire, for hand operation in manipulating such disconnect receptacle (also known as a clip) onto a conventional contact tongue, the latter frequently being immobile because it is mounted in a fixed relation on electrical apparatus or as a part of the stationary disconnect binding post thereof.

Accordingly, an object of this invention is to provide a quick-disconnect electrical terminal receptacle for singlewire conductors, characterized by simplicity, together with an improved pressure or spring-loading contact means for engagement with a conventional contact tongue, the latter being adapted to receive my new receptacle which is 4 readily plugged onto and guided into current-transmitting position thereon and pulled oif thereof by a freely sliding disconnect action.

This specification with its claimed subject matter and accompanying drawings explains the invention as preferred and embodied at this time for an understanding of the problems sought to be solved. Since the teachings herein may suggest structural changes to others who wish to avail themselves of the benefits of the invention, it is pointed out that subsequent modifications hereof may well be the same in spirit and principle as this disclosure.

The drawings are made on a somewhat larger scale than the usual commercial size of this disconnect terminal receptacle. Its front or inner end (being the contact end) is at the left in the views. The rear or outer end is at the right on the drawings and permanently connects with a suitable length of insulated flexible Wire a known way for the purpose of reaching and establishing convenient contact engagement with electrical apparatus.

Fig. l is a perspective View of the terminal receptacle die-and-punch formed from flat sheet metal.

Fig. 2 is a transverse section developed along the plane of line 2.

Fig. 3 is a mid-longitudinal section through the entire length of the terminal receptacle and which is shown as having been manually pushed or plugged into embraced disconnect pressure contact relation onto the free end of a conventional type of stationary contact tongue. The other end (at the left) of the contact tongue is shown diagrammatically as an electrical connecting stationary binding post on a wiring panel or other apparatus in circuit with the contact tongue and my novel receptacle.

Fig. 4 is a transverse section on the line 4, as a further illustration of the receptacle in pressure engagement with the contact tongue.

Further reference is made to the drawings for a more detailed description of the invention. However, an explanation first is made of one form of conventional disconnect contact tongue frequently found embodied in electrical apparatus, as indicated in a general way in Figs. 3 and 4, and for which my new terminal receptacle has been made to cooperate with an improved mode of action and functional advantage.

One known and simple form of disconnect contact tongue comprises an elongated straight conductive (copper) strip CT of fiat bar stock. it has parallel side edges, with an outer or front free end (at the right in Fig. 3). This contact tongue CT is of smooth-surface and imperforate form with ovalled or chamfered edges for convenient piloting entry into the terminal receptacle (Fig. 1) comprising this invention. Such tongue CT is a male terminal and usually has its rear end screw-fastened or otherwise secured in a stationary manner to electrical apparatus as represented by a wiring panel P. A conductive screw illustrated with the panel P may be taken to indicate a conventional quick-disconnect binding post having an electrical wire connection (not shown) adapted to be attached to it in a known manner.

Accordingly, the wiring panel P and disconnect contact tongue CT are shown schematically in Fig. 3, being explanatory of conventional terminals of the male type permanently carried on a wiring panel, condenser, battery, or other apparatus, and with which this new receptacle cooperates. Fig. 3 is an illustration of the environment of the invention and is in aid of understanding the improved mode of operation herein.

Contact terminals CT of the straight flat tongue type lack tensioning or spring-loading means. They are inherently iner. insofar as concerns the making of a good electrical connection under mechanical pressure with a mating terminal receptacle. One of the problems of this invention is to produce an effective terminal receptacle having spring-loading means useful with the simple type of straight edge disconnect tongue and melting an effective connection therewith.

Coming now to a description of the inventive concept, as illustrated by one preferred example of construction, there is shown a terminal receptacle body part indicated generally at lil, being the front end and contact portion of the connector. The body 10 is elongated, may be of generally flat form, and rectangular in shape, thus having parallel sides.

The body 10 is usually made of nominally-hard metal lie-bar stock (copper sheet) which is tempered to resist any tendency to bend permanently out of shape when subjected to stress during use. And moreover, the temper imparts resiliency for inducing fiexure by which to springload it and thereby provides a reactive (return) tension into the contact portions of the body 10 when it is plugged into electrical connecting position onto the stationary disconnect contact tongue CT, as in Figs. 3 and 4.

The r ar end of the elongated rectangular body i is provided with any suitable means, such as a conductive sleeve or barrel 11, for permanently connecting a flexible conductor (wire W) therewith in a known way. In this example of the invention, the wire-receiving sleeve 11 is shown integral with the rear end of the body 10. One

known practice is to make a solderless connection by annularly compressing the sleeve as a whole, or by segmentally indenting a portion thereof, onto the bare conductor wire strands W at the end of a length of insulated flexible wire, thereby permanently and homogeneously unifying the sleeve and strands.

The one-piece terminal receptacle (its body as a whole) is characterized by a centrally disposed long fiat contact surface 13 of irnperforate form extending from end to end thereof. Throughout the body length, the contact surface 13 is in one plane, Without die-forming mutilation, thus presenting a contact surface of maximum area for effective engagement with the male contact tongue CT when the body 10 is pushed onto it.

An arch 14 is formed on each lengthwise side of the body, hence two arches, parallel to each other, and above the elongated imperforate contact surface, i. e., spaced from it. The arches 14 have their ends integrally formed at the front and rear ends of the body 1%) and are about the same length as the contact surface 13. Thus the two arches are symmetrically disposed on each side of the long contact area 13 of the receptacle. The arched portions 14 are resilient, the elastic characteristic of which causes them to tension and spring-load, as later noted.

Each arch 14 is defined by two inner straight edges 15 in the same plane and which are parallel to the long axis of the contact surface 13. The two straight edges 15 of either arch may as well be regarded as a single edge because one is a continuation of the other. Consequently, there are two straight edges 15, one on each side of the long irnperforate contact surface 13, parallel to each other, and facing one another, in spaced symmetrical relation to said contact surface of the body 10. Of importance is the fact that these are long guiding edges 15, spaced apart a distance slightly greater than the width of the contact tongue CT, for piloting this terminal receptacle thereonto. This relation of parts is also shown in Fig. 4.

Next, it is seen that each arch, at its center, carries a contact lip 16, hence a pair thereof, disposed inwardly. Each arch supports its contact lip 16 in spaced relation from the plane of the body contact surface 13 a distance which, fractionally, is less than the thickness of the contact tongue CT heretofore described. Not only that, but the two lips (their inner contact surfaces) are parallel to the main contact surface 13 of the body 10. Thus the two lips 16, like other portions of the body 10, are symmetrically disposed, extend toward each other, but are spaced apart, across the imperforate contact surface 13.

It is believed that the foregoing description covers the relation of the several integral portions of the body 10 by which an electrical disconnect one-piece receptacle is die-formed from a single sheet metal piece. The drawings also show the dimensional relations between the several integral portions.

In use, it is seen that when plugging this new receptacle 10 onto the long contact tongue CT, the latter is piloted into place by the spaced pair of long guide edges 15 of the two arches 14. Accordingly, the single contact tongue CT slides under the two spaced contact lips 16. The latter yield outwardly by reason of the resiliency of the two long arches 14 which give slightly under the pressureentry of the contact tongue. Thus the entire body is ten sioned-particularly so as to the two arches 14-and spring-loading follows, the reaction of which mechanically compresses the long imperforate maximum-area contact surface 13 of the body against the contact tongue CT.

The foregoing new construction and novel mode of operation provides a given minimum-size disconnect receptacle 1G with maximum-contact area on and against the simple type male terminals CT. The connect and disconnect operation between the two parts is smooth and requires minimum manual effort as compared to the resulting degree of augmented compression between the parts, which makes for an effective electrical connection, and which is free of any and all notched or latching-detent means so prevalent in the art for holding two connector parts together.

This disclosure explains the principles of the invention and the best mode contemplated in applying such principies, so as to distinguish the invention from others; and there is particularly pointed out and distinctly claimed the part, improvement or combination, which constitutes the invention or discovery, as understood by a comparison thereof with the prior art.

What is claimed is:

An electric spade terminal receptacle, for quick-connect and disconnect engagement with a conventional smoothsurface imperforate contact tongue adapted to be received thereinto; comprising an elongated rectangular shaped body, having means to receive a wire adapted to be permanently connected therewith, and said body also having a contact surface, also of fiat imperforate form, disposed centrally from end to end of said body, and hence for the full length thereof; an arch formed along each parallel lengthwise side of the body, thus two arches symmetrical with and spaced from each other on and with said body, the arches defining two long guiding edges facing each other across the long flat contact surface for piloting the terminal receptacle onto the smooth-surface imperforate contact tongue, the ends of said arches being formed integrally with the ends of said body, each arch spanning the body lengthwise, and having resilient flexure in relation to the long fiat contact surface; a contact lip carried by each arch, overhanging and spaced from the long flat contact surface, the two contact lips being fiat, with the entire area of each lip disposed parallel to said long flat imperforate contact surface, and extending toward each other, centrally and transversely of said long fiat contact surface, and in symmetrical relation therewith; the terminal receptacle being slidable onto the smoothsurface imperforate contact tongue aforesaid, the facing edges of the two arches acting to guide said terminal receptacle onto said tongue, with the entire area of the two contact lips resiliently engaging said tongue under frictional pressure, thereby urging the two arches resiliently outward from the long fiat contact surface, and springloading said arches, which react under tension, to exert pressure between the smooth-surface imperforate contact tongue and said long flat imperforate contact surface.

References Cited in the file of this patent UNITED STATES PATENTS 2,336,385 Batcheller Dec. 7, 1943 2,550,636 Bergan Apr. 24, 1951 

